Our krishna is PURNA PURUSHOTTAMA or the sublime of all persons.Heis controller of all qualities (Guna Vigraha) and he is Nirgun.Shri Krishna,He is above the nature or Prakruti and Nirgun.Our Prabhu is nirgun and does not consist of panch mahabhut tatvas(elements) viz.prithvi,jal,vayu, tej and aakash. But HE consistes of Anand(Bliss) only.

Its known that Vishnu is satvagun pradhan and hence within the Prakruti

TranslationBeing completely devoid of impurities and having all Devine attributesSHIVA and VISHNU have been mentioned in their respective scriptures.Although both of them are capable of giving the awards of worldly happinessas well as salvation, shiva awards salvation and vishnu awards worldlyhapiness. Even in the world also, the master does not anytime give awaywhat he enjoys. (13,14)

SO as per above we should pray Shiva if we want worldly happiness andVishnu for salvation or moksha.

But as a Pushtimargi vaishnav,we do not want both of above because both arenot permanent.

When we consider the Institutions like Iskon, then we must know the clarification that Iskon Instituon is not a Sampraday, it is just a Thought taking the idiology of ShriKrishna Chaitanya by the follower ShriPrabhuPada. So it is not the Sampraday. And we cannot consider that ShriKrishna Chaitanya was the person who had extablished Iskon.

I call Iskon as an institute. Because it is not a Sampraday. Just as any social group running between few peoples, may and they form some NGO's. Similarly This Institute is following the Bhaktimarg as been carried by ShriKrishna Chaitanya. But ShriKrishna chaitanya was not the Aacharya of any sampraday. May many of the jeevs got in touch with ShriKrishna Chaitanya looking towards the Utkat (high) avastha of Devotion and the Pure form of Devotion.

Just as in our sampraday 1 sevaka of Shrimahaprabhuji i.e. Surdasji, before got in touch with ShriMahaprabhuji, Surdasji was known as SurSwami and had many many of the sevaks. But Surdasji didn't had any sampraday. And he followed a sampraday of ShriMahaprabhuji.

ShriKrishna Chaitanya didn't followed any sampradaya, but with the High blessing Devotion He attained the pure form of ShriKrishna Bhakti.

Prakashji, one of ur question was remained unanswered i.e "why do you call moksha as not permanent. I thought it was the end of it"

In Balbodh Granth Shri Mahaprabhuji has given His opinion on various Rushimunis(Sages) thinking on Moksha. Aapshri discusses four swaroop of moksha or rather describes it in four ways.

1. Moksha Sankhiya Shastra (The Arithmetic of Moksha). In this section one has to be humble towards his knowledge-his life and his duty in religious life. When one understands this, that understanding is known as Moksha in its infant stage. The infant stage is accountable and is measurable in terms of how much humble entity is being acknowledged for salvation in religious life, and this measure is known as Ganit or Sankhiya Shastra.

2. Moksha Yog Shastra (The Habits and disciplines Moksha). This Moksha is where in religious life how much one does "Yam-niyam-asan-pranayam" that is how ones uses discipline in prayers, and how persistent is the timing, sitting in yoga position (Samadhi avastha) and the regulation in bowing with humble gesture. This system of discipline is known as Yogshastra. How much one is ready to take system and by-laws of the religion and is able to follow it with disciplined regulation, this is known as Yog and the end result is moksha.

3. Parto Moksha (Pashupatra saivatantra moksha) According to this moksha, one gets this moksha with the grace depicted by Lord Shiva. One has to be innocent, with Brahma and its full virtues that acknowledge the Shiva style leela. And this way Brahma Shiva leela can bestow this moksha. But this moksha does not entail anand moksha, that is to say that Shiva enjoys anand moksha so he will not bestow this moksha. He only bestows Bhog (material life requirements and its uses but might not entail satisfaction as it does not result into happiness) instead of anand. Although, sometimes Shivji does appeared to give happiness (anand) but it is a rare case. This anand is sometimes bestowed on His ardent follower who has accepted the total surrender and has accepted Varnashram dharma and practices it word by word.

4. Panchrantra Vaishnavtantra Moksha. This moksha is bestowed by doing Sadhan seva of Shree Vishnu Bhagwan. Vishnu normally gives Moksha and in very rare cases Bhog is bestowed when one has accepted complete and total surrender. In this moksha all domestic and material happiness is bestowed and then takes one to Parto Moksha with Panchrantra takes Pushti jagruti (awakening).

After discussing the various Moksha sections and how it is can be achieved, Shri Mahaprabhuji is preparing the Balak of Pushtimarg and advises vaishnavs not to wonder in mines of Moksha. In this Granth, He shows the way to be in a position to go beyond the Moksha.